The subject application relates generally to agricultural harvesters. In particular, the subject application relates to hydraulic systems for a header of an agricultural harvester in which the hydraulic systems of the header connected to the harvester share a hydraulic fluid reservoir.
Agricultural harvesters such as combine harvesters are well known apparatuses for harvesting grain crops. An agricultural harvester is typically a self-propelled vehicle which includes a feederhouse and mechanisms downstream of the feederhouse for separating grain from other crop material. A header is attached to the front of the harvester and includes mechanisms for cutting crop, gathering crop and delivering crop to the harvester's feederhouse.
As typically constructed, a combine harvester includes a hydraulic system which powers various subsystems of the harvester and the header. The hydraulic system includes a hydraulic fluid reservoir and one or more hydraulic pumps that can derive their motive force from power take offs (PTOs) directly or indirectly connected to the drive train of the harvester. The hydraulic pumps are in fluid communication with one or more hydraulic motors which drive equipment such as the harvester's steering and transmission subsystems as well as certain header subsystems such as harvesting reel rotation and position adjustment. However, in typical harvesters, header subsystems such as draper conveyor drives, auger drives and cutter drives are sustained by their own hydraulic systems, e.g., hydraulic systems that are independent of the combine's hydraulic system. These header subsystems include their own discrete reservoirs, filters, pumps, valve blocks and motors. As a consequence, there is added complexity, weight and cost associated with current header hydraulic systems, as well as the burdens of maintenance of the oil levels and filters of such systems.